To assess sorption and solubility of several bulk-fill and conventional resin- composites after one-year storage in water and artificial saliva (AS).
Six bulk-fill (SureFil SDR, Venus Bulk Fill, X-tra base, Filtek Bulk Fill flowable, Sonic Fill, and Tetric EvoCeram Bulk Fill) and eight conventional resin-composites (Grandioso Flow, Venus Diamond Flow, XFlow, Filtek Supreme XTE, Grandioso, Venus Diamond, TPH Spectrum, and Filtek Z250) were tested. Disc shaped samples (n= 5) were randomly immersed into distilled water and AS for one-year period and weighed at different time intervals. Data were analysed using repeated measures ANOVA, one-way ANOVA, and Tukey's post hoc test (α=0.05).
In water, all materials (with the exception of X- Flow) reached a stable mass within three months with a slow increase observed in AS up to one year. Sorption values in water and AS for most materials were not significantly different (p≥ 0.2). Sorption and solubility values in water ranged from (6.5μg/mm3 and -1.77μg/mm3 respectively) for X-tra base to (78.8μg/mm3 and 44.77 μg/mm3 respectively) for X- Flow (p< 0.005). Sorption of the polymer matrix in water ranged from 1.18 % for XB to 9.95 % for XF.
Water sorption and solubility of resin-composites are material-dependent and highly affected by the filler loading and hydrophilicity of the resin matrix. BisEMA and UDMA-BisEMA based resins appeared to be more hydrophobic than BisGMA based systems. Water and AS, are generally comparable as storage media in terms of water sorption.